/* SQUIB - Scala's Quirky User Interface Builder 
    Copyright (C) 2008 Tim Dalton

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
*/

import scala.collection.mutable.HashMap 
    
package tfd.scala.squib {

    import java.awt.Component
    import java.awt.event.{KeyEvent, KeyListener}
    import java.util.EventObject

    // Since descendents of JSlider and JSpinner have addChangeListener method but not from
    // an common ancestor or interface, we'll have to resort to structural typing
    trait FiresKeyEvents[T <: {  def addKeyListener(kl:KeyListener) }] { self:FiresEventObjects with IdableTrait =>
        self.eventHandlers += (keyEvents _).asInstanceOf[(Object, HashMap[String, EventObject => Unit]) => Unit]

        def keyEvents(comp: T, events:HashMap[String, EventObject => Unit]):T = {
            val handler = new DelegateKeyEventHandler(events);
            if (handler.hasEvents) {
                comp.addKeyListener(handler)
            }
            comp
        }

        class DelegateKeyEventHandler(events: HashMap[String, EventObject => Unit]) extends KeyListener {
            private val keyPressedDelegate:Option[KeyEvent => Unit] = events.get("keypressed");
            private val keyReleasedDelegate:Option[KeyEvent => Unit] = events.get("keyreleased");
            private val keyTypedDelegate:Option[KeyEvent => Unit] = events.get("keytyped");

            lazy val hasEvents = !(keyPressedDelegate.isEmpty
                                   && keyReleasedDelegate.isEmpty
                                   && keyTypedDelegate.isEmpty)

            override def keyPressed(ke: KeyEvent) {
                if (!keyPressedDelegate.isEmpty) keyPressedDelegate.get.apply(ke)
            }

            override def keyReleased(ke: KeyEvent) {
                if (!keyReleasedDelegate.isEmpty) keyReleasedDelegate.get.apply(ke)
            }

            override def keyTyped(ke: KeyEvent) {
                if (!keyTypedDelegate.isEmpty) keyTypedDelegate.get.apply(ke)
            }
        }
    }
}